Jakub Korab

Random musings of a restless mind.

  • How to reason about queue depth graphs

    Occasionally I come across something that seems really obvious to me, but actually isn’t obvious from an outsider’s perspective. A few weeks ago I spent some time with a client (and their client) in trying to understand the behaviour of a message-driven platform that made heavy use of ActiveMQ. Without going into too many details, […]

  • Java DSLs for ActiveMQ config and testing

    As part of a larger project that I am working on, I needed to define numerous different ActiveMQ configurations inside non-trivial integration tests. Rather than instantiating brokers by hand using the internal ActiveMQ classes, or writing lots of similar-but-different XML configurations, I wrote a pair of Java DSLs to allow me to quickly spin up […]

  • Digesting Microservices at muCon

    On Friday, I had the privilege of presenting at the very first Microservices conference – muCon. In my talk, Engineering Sanity into Microservices, I spoke about the technical issues surrounding state in distributed systems as a whole, how these become a bigger problem as the number of deployed services goes up, and a few suggested […]

  • Running ActiveMQ Replicated LevelDB on VirtualBox

    I have wanted to spend some more time recently playing with Replicated LevelDB in ActiveMQ. Not wanting to hit a cloud environment such as EC2, I set up 3 VirtualBox nodes on my workstation running Fedora. The host system needs to be fairly beefy – you need at least a dedicated CPU core per image […]

  • ActiveMQ Network Connectors Demystified

    When trying to get your head around how ActiveMQ’s networks of brokers work, it helps to have an understanding of the underlying mechanisms involved. I’ve always thought of it as the “Lego brick model” – once you understand the smaller pieces, you can reason about how they can be combined together. When a regular client […]

  • Gabriella

    Born early morning on Monday the 17th of March. Mum and baby are back home and doing well. Older sister very excited! Daddy very excited to see some sort of balance restored to the household 🙂

  • Camel Cookbook Launch at LJC, March 5th

    After all the hard work comes the fun. On Wednesday 5th of March, I will be giving a presentation entitled “Effective System Integrations with Apache Camel” at Skillsmatter, in London; hosted by the good folks from the London Java Community. The evening will kick off at 6:15, and I’ll be headlining 😉 at 6:45. The […]

  • Apache Camel Developer’s Cookbook

    I am pleased to finally announce the reason that I have fallen off the face of the Earth over the past year – myself and Scott Cranton have just finished writing the Apache Camel Developer’s Cookbook. The book will be published by Packt Publishing later this month. It is available for pre-order on the Packt […]

  • Monitoring ActiveMQ via HTTP

    29/4/2014 The following information is a little bit stale. Since version 5.9.1 of ActiveMQ, Hawt.io is no longer part of the ActiveMQ distribution from Apache, but Jolokia is. Jolokia runs on http://localhost:8161/api/jolokia by default, so if you keep this in mind while reading this post, the remaining instructions are still correct. Dejan Bosanac has written […]

  • Now consulting independently

    After a long time working as a consultant for others, I felt that the time was right to take off the training wheels and break out on my own. Earlier this month, I re-focused my company Ameliant to independent work, delivering consulting around the Apache suite of integration technologies that I have been blogging about […]